In the past, rock crusher designers have endeavored to improve the ease of maintaining horizontal shaft impact rock crushers. While many improvements have been made to reduce the expense associated with repair and maintenance of such crushers, removal of all of the breaker plates on such crushers remains a non-trivial task. Most crushers usually have two breaker plates. A primary breaker plate is disposed nearest the feed opening and nearest the top of the crusher. These crushers typically have a secondary or rear breaker plate, which is generally located lower in the crusher and more toward the rear of the crusher. Some attempt has been made to reduce the removal time for the primary breaker plates. One example is the crusher shown in U.S. Pat. No. 6,089,481 entitled APPARATUS FOR RELIEVING THE LOAD ON ADJUSTING RODS OF A CRUSHER, issued to Gregory A. Young. This patent shows a primary breaker plate pivot shaft disposed near a front edge of the tiltable portion of the crusher. When the crusher housing is tilted for repair, the pivot shaft of the primary breaker plate can be lifted out of the crusher while the breaker plate is still attached. Another example of an attempt to reduce the removal time for primary breaker plates (or curtains, as they are sometime called) has been to hang one or more of them on a single cradle. However, it is typical that when a repair is needed on any of the breaker plates, the breaker plate pivot shaft, which is typically directly coupled to each of the breaker plates and typically extends wall-to-wall across the crusher, (a directly coupled trans-crusher pivot shaft) is either driven or pulled from the crusher, and then the breaker plates may be removed.
While this approach of driving or pulling the pivot shaft prior to breaker plate removal has been used extensively in the past, it does have some drawbacks. First of all, depending upon the condition of the breaker plate pivot shaft (which can be bent), or any distortion of the breaker plate itself, or the crusher frame, this can involve significant effort and can leave the crusher out of service for an extended time period.
Consequently, there exists a need for improved methods and systems for rapidly removing and replacing all of the breaker plates in horizontal shaft impact rock crushers in an efficient manner.
It is an object of the present invention to provide a system and method for repairing and maintaining a horizontal shaft impact rock crusher in an efficient manner.
It is a feature of the present invention to utilize directly coupled trans-crusher pivot shafts mounted in slots with movable structures for permitting rapid access to the shafts and thereby permitting rapid removal of all breaker plates, with the breaker plate pivot shaft remaining therein.
It is another feature of the present invention to utilize short pivot shafts or pins mounted in slots with movable structures for permitting rapid access to the pins or shafts and thereby permitting rapid removal of all breaker plates, with the breaker plate pin or shaft remaining coupled thereto.
It is an advantage of the present invention to achieve improved efficiency in replacing the entire complement of breaker plates in horizontal shaft impact rock crushers.
The present invention is an apparatus and method for repairing and maintaining horizontal shaft impact crushers which are designed to satisfy the aforementioned needs, provide the previously stated objects, include the above-listed features, and achieve the already articulated advantages. The present invention is carried out in a xe2x80x9cwasted time-lessxe2x80x9d manner in a sense that the time consumed with separating (driving or pulling apart) a breaker plate and its associated pivot shaft prior to removal of a breaker plate from a crusher, has been eliminated.
Accordingly, the present invention is a system and method including a horizontal shaft impact crusher having a movable breaker pivot shaft slot cover or retaining member which permits access to and removal of a pivot shaft from a void near a periphery of the crusher while the pivot shaft remains directly coupled to the breaker plate.